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Apache Commons Compress software defines an API for working with compression and archive formats. These include: bzip2, gzip, pack200, lzma, xz, Snappy, traditional Unix Compress, DEFLATE, DEFLATE64, LZ4, Brotli, Zstandard and ar, cpio, jar, tar, zip, dump, 7z, arj.

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.commons.compress.utils;

import java.util.Collection;
import java.util.Iterator;
import java.util.Objects;

/**
 * Iterator utilities.
 *
 * @since 1.13.
 */
public class Iterators {

    /**
     * Adds all the elements in the source {@code iterator} to the target
     * {@code collection}.
     *
     * 
     * When this method returns, the {@code iterator} will be "empty": its
     * {@code hasNext()} method returns {@code false}.
     * 
     *
     * @param  type of the elements contained inside the collection
     * @param collection target collection
     * @param iterator source
     * @return {@code true} if the target {@code collection} was modified as a
     *         result of this operation
     */
    public static  boolean addAll(final Collection collection, final Iterator iterator) {
        Objects.requireNonNull(collection);
        Objects.requireNonNull(iterator);
        boolean wasModified = false;
        while (iterator.hasNext()) {
            wasModified |= collection.add(iterator.next());
        }
        return wasModified;
    }

    private Iterators() {
        // do not instantiate
    }

}